Re: Going from 13 hrs sleep straight to very little... HELP PLEASE
I would vote teething as well. My son is 13 months and sleeps through the night except when he is getting a tooth. The way you can tell is when you pick him up, does he stop crying right away or within a minute or so? If he doesn't, he is in pain of some sort.
Also is he pulling up on stuff? A lot if gross motor development happens around 9 months so they start to regress sleepwise.
Loving wife to my gaming, sports loving hubbie. Sahm to J 2/12 and L 10/13